This study aimed to explore the impact of health literacy on psychosocial and behavioural outcomes for people who were not at high risk of cardiovascular disease receiving a hypothetical blood pressure reading of 135/85 mmHg. We performed a secondary analysis of data from a national sample of Australians aged 40 to 50 years (n = 1318) recruited online. Health literacy was measured using the validated Newest Vital Sign (inadequate: 0-3; adequate: 4-6). Analysed outcomes included: willingness to increase exercise and accept medication; perceived severity; positive and negative affect; illness perceptions and impacts on life and motivation. Participants with inadequate levels of health literacy perceived a blood pressure reading of 135/85 mmHg to be less serious compared to individuals with adequate health literacy (Mean Difference [MD]:0.21; 95%CI 0.03-0.39; p = .024; d = 0.13), and reported less motivation to eat well (MD:0.44; 95%CI 0.31-0.58; p < .001; d = 0.38) and exercise (MD:0.43; 95%CI 0.31-0.58; p < .001; d = 0.36). However, they were more willing to accept medication (MD:0.20; 95%CI 0.07-0.34; p = .004; d = 0.17). Participants with inadequate health literacy also perceived the condition to have fewer negative impacts on aspects of life and work than individuals with adequate health literacy, but reported greater negative emotion and more negative illness perceptions (all p < .001). Tailored communication and behaviour change support may be needed when communicating blood pressure information to people with lower health literacy and not at high risk of cardiovascular disease given the differential impacts on medication (increased willingness) and healthy exercise and diet behaviours (decreased willingness) observed in this study.